You should definitely hire a professional to be sure you get rid of all it. Mold can cause so many health problems! My brother-in-law actually owns a company in Loveland, OH that deals with water damage and mold remediation. You should check out his website at http://www.floodteam.com. Give them a call and have them come out and give you a quote. :)
I hope this helps!
Howard Hanna Real Estate
But more importantly, instead of just removing the mold, it's important to remove the cause of the mold. The conditions that created mold, if they continue to exist, the mold will return.
Mold requires a food source and a water source to grow. High humidity, leaks, lack of ventilation, dark dank basements, or sometimes bathroom vents that terminate in your low ventilated attic, can breed mold. Repair the leak, add ventilation, put the vents through the roof ... whatever your professional suggests you need to do.
And then remain vigilant.
Hope this helps.